Posts Tagged ‘Biodiversity’

“The rate of change has never been that fast before” – Dr. Bell

Monday, September 15th, 2008

If you like listening seminars with funny but high-quality speakers in a little and pretty mysterious auditorium, September 11th 2008 at 6 pm in the Redpath museum auditorium was one of those nights.  Dr. Graham Bell is a world-renowned scientific experimental evolutionist and evolutionary ecologist at McGill University and his seminar was a really nice example of a combination of his scientific work and the new global issue; Climate change.  He made a funnel effect to his presentation by introducing large biological concepts and finishing with really precise questions related to his laboratory work.  Before letting people leaving the auditorium, he also clearly identified how this global event may alter biological communities.

In front of packed audience and after his introduction by the chairman, Dr Bell did not wait too much time and jumped feet first in the great word of biology by describing simple biological concepts.  The first one was how species reacts when facing to environmental stressors.  Some species migrate, some adapt and others.  A simple example of how science works.  Water fleas have been introduced as an example of species who adapt (change body shape) themselves in presence of predators.  The second response suggested was migration and explained that plant evidences are obtained through the pollen record.  The last type of response is extinction.  Dr. Bell gave all kinds of example.  He explained that fossil records are abundant and proved most of the extinction currently known.  Mammoths, Moa, Thyadacine, Giant Beaver, Giant Ground Sloth, River dolphin are all extinct species mostly gone by human pressure.  Suddenly, a huge and cold wave of exasperation has hit the auditorium and people have changed their smile to a much more exasperate face.  Dr. Bell tried to rescue the audience by throwing a life buoy called “rapid evolution”.  He has secured the crowd by suggesting famous evolutionary experiences like the two variations of moth type (black and white) in Great Britain and a weed (Vicia sativa) that has been continuously been harvested with regular crops and the plant has evolved in a way that its seeds is no longer identical to the wild type but resemble more to the seed of the crops.

Everyone was then ready to receive the second cold wave of the presentation.  Climate change is the biggest challenge of the human history because it does not affect one species at a time but the entire community.  This is the biggest change that human are facing today because it introduces three type of complications. 

1) How biodiversity will react?

2) How the complexity of an ecosystem will evolve?

3) What will be the species evolutionary change?  


After explaining global issues, he introduced his research to explain how CO2 can drive the evolutionary response to algae.  He found that algae can evolve rapidly.  At high CO2 level,  algea had higher rate of respiration and photosynthesis.  They had also an higher chlorophyll content but reduce in size.  However, these cells were not able to survive when CO2 level went back to normal concentration.  Even if some species are able of rapid evolution, Dr Bell insisted that most of the species are not able to evolve at a fast rate and concluded that the rate of change has never been that fast before.  

Finally Dr. Bell has clearly well identified the type of audience he had in front of him and has adjusted his presentation accordingly.  He had the ability to manipulate the emotions of his audience (like rollercoaster) even if the topic of his presentation does not announce “good news”.  He is not shy to say “we don’t know” as an answer which makes him opened minded (important in science).  This presentation finished with a small snack at the Redpath museum lobby.  This is a really nice idea because it allowed people to discuss of their impressions.  However, I was not able to make it since people at MAC were waiting for me for a soccer game!  Next time, I’ll be… Present!  🙂